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Re: LMS-5400 / RL-p18" buy-in

Even if we assume the Crown amp has infinite power capabilities, I still look back to the TC2k tested outdoors at 2m with 2000 watts on a 115db sweep down to 10hz with no highpass and no bottoming or other mechanical driver issues. I'd hope an 18" with higher rated excursion capabilities from the same company could at least do that at 6db louder at all frequencies.
 

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Re: LMS-5400 / RL-p18" buy-in

I definitely understand where you are coming from. But that scenario and Jai's situation really can't be compared directly.

But there is no need for speculation when Ilkka himself will be fully testing the 5400 in a very similar alignment using a practically identical power setup. His observations and findings will be be more conclusive, wouldn't you say?
 

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Re: LMS-5400 / RL-p18" buy-in

But I still say he shouldn't have to tune at 16hz with a 16hz highpass - wasted potential.
And I never disagreed with you there. :whistling: I too think he should be able to use maybe a 13Hz 2nd order BW, at least judging from the simulations.
 

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Re: LMS-5400 / RL-p18" buy-in

Lets be real though, you're talking about purposefully playing them +6dB hot and cranking them up. That isn't a real world scenario.



Well there were some other things going with Jai's setup early on. We'll know the full story with Ilkka's setup...but you are probably underestimating these CE4000s, to be honest. They really are beasts. And you got it mixed up, one shouldn't question the claimed xmax spec. Remember Steve, its the xmech that determines the mechanical limit. And that would be the only problem with the 5400, it doesn't have as much throw past xmax as a lot of other drivers have.
Agreed, it is not everyday real world usage, but you will agree that some of us do crank it up at times, don't we. It doesn't take much power to bottom out this design below tuning. In terms of listening experience setting the HP at 20Hz vs setting at 16Hz, did not make any noticeable difference for the several movies I tried. Except for the fact that, with the 20Hz setting of the 2nd order BW, I could safely push beyond reference (on any material to date) without reaching the subs limitations. Now transformers is coming out shortly. Could be a WOTW killer. With more and more demanding LFE tracks, it is better to be conservative.
 

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Re: LMS-5400 / RL-p18" buy-in

And I never disagreed with you there. :whistling: I too think he should be able to use maybe a 13Hz 2nd order BW, at least judging from the simulations.
All that I am saying is, start with 20Hz and then go lower. Proceed with caution. I have seen it happen and it is not pretty. 13Hz 2nd order BW? no I don't think so. Not with this design and tuning. His tests will tell.
 

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Re: LMS-5400 / RL-p18" buy-in

Even if we assume the Crown amp has infinite power capabilities, I still look back to the TC2k tested outdoors at 2m with 2000 watts on a 115db sweep down to 10hz with no highpass and no bottoming or other mechanical driver issues. I'd hope an 18" with higher rated excursion capabilities from the same company could at least do that at 6db louder at all frequencies.
Something to keep in mind. A sweep is different from real world movies. Set the 2nd order HP filter to 13Hz, calibrate to 80dB reference at LP in a large room (6000 cu ft plus) and with a similar design as mine (which this sub is), this will bottom out. It did in my room. And I have tried different drivers. Now what I observed may not show up in sweeps. Maybe the input level was higher than 115dB, who knows, I didn't measure what the input level is.
 

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Re: LMS-5400 / RL-p18" buy-in

If you are absolutely certain, and other owners are as well, then there is something amiss with this driver. There are quite a few of us LLT owners out there, and we use larger enclosures with low tunes, no highpass filters, and drivers that are supposed to have less excursion capabilities than the LMS 18, and there hasn't been bottoming yet, not with real material. Now I really want to see this design tested.

Also, I agree that the difference between reproduction of material at 20hz and 16hz will be extremely hard to notice, however, being flat and solid to 10hz as compared to 20hz is a different story.
 

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Re: LMS-5400 / RL-p18" buy-in

then there is something amiss with this driver.
however, being flat and solid to 10hz as compared to 20hz
There's nothing amiss with this driver. Bottoming a speaker is NOT hard to do and doesn't necessarily take lots of power.
Perhaps what this driver can do that others can't is reproduce 10hz to 20hz flat, solid, AND LINEAR with less distortion. The long stroke and unique motor design allow the LMS to operate loud, low, and linear.
The maximum spl of the LMS driver at a given FR depends on the particular application. The long stroke and unique motor design allow the LMS cone to easily move to it's XMAX because of the length and strength of the magnetic field produced by the huge magnet structure. I haven't seen another driver with a magnet structure as large as the LMS.
Ilkka's upcoming full series of tests will answer most of our questions about the LMS and it's behaviour in-box. No more need to speculate or extrapolate from software modeling programs.
Hang on Steve.
 

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Re: LMS-5400 / RL-p18" buy-in

If you are absolutely certain, and other owners are as well, then there is something amiss with this driver. There are quite a few of us LLT owners out there, and we use larger enclosures with low tunes, no highpass filters, and drivers that are supposed to have less excursion capabilities than the LMS 18, and there hasn't been bottoming yet, not with real material. Now I really want to see this design tested.

Also, I agree that the difference between reproduction of material at 20hz and 16hz will be extremely hard to notice, however, being flat and solid to 10hz as compared to 20hz is a different story.
I don't think there is anything wrong with this driver either. Some WinISD models give some indication why a filter like I describe is needed. It performs according to spec and it performs awesome.
 

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Re: LMS-5400 / RL-p18" buy-in

Bottoming a speaker is NOT hard to do and doesn't necessarily take lots of power
Ermm, again, TC2k, 2000 watts, 115db sweep down to 10hz outdoors 2m groundplane, no highpass filter, and no bottoming. That's just one design too.

No more need to speculate or extrapolate from software modeling programs.
I'm doing no such thing. You guys are telling me that you are bottoming your LMS 18" drivers if tuning below 20hz without an extremely aggressive highpass filter.


Ilkka, last I recall, you said you won't be testing this until next Spring - does that still hold true?
 

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Re: LMS-5400 / RL-p18" buy-in

Ermm, again, TC2k, 2000 watts, 115db sweep down to 10hz outdoors 2m groundplane, no highpass filter, and no bottoming. That's just one design too.
It was a 110 dB sweep.


Ilkka, last I recall, you said you won't be testing this until next Spring - does that still hold true?
Definitely not. ;)
 

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Re: LMS-5400 / RL-p18" buy-in

Ermm, again, TC2k, 2000 watts, 115db sweep down to 10hz outdoors 2m groundplane, no highpass filter, and no bottoming. That's just one design too.
Wrong. At 115dB sweep 2kW wasn't enought because the amp clipped. Don't you remember, the 115dB sweep was incomplete. ;)
 

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Re: LMS-5400 / RL-p18" buy-in

My concern for Ilkka and the LMS is that he holds a now rare specimen and that he waited months for shipment across the ocean for this opportunity. He also is handling a driver who many of us helped pay for. We all want success whether or not the driver meets our expectations.
It would be a sad sad experience if something unnatural or unexpected happened to the driver while Ilkka was in the process of assembling or testing and since some of us have experienced what we think was "bottoming" during our own trials, we want Ilkka to be watchful as his tests proceed. That's all.
 

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Elite Shackster
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Re: LMS-5400 / RL-p18" buy-in

You don't have to worry any more. The testing is already done and both drivers are still live and kicking. And they did DELIVER. :)
 

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Re: LMS-5400 / RL-p18" buy-in

Congratulations Illka! And thank you for your persistence and audiologic spirit of adventure! Not to mention having lived through endless comments from some of us who are worse naggers than a 65 year old woman on diet coke.
 

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Re: LMS-5400 / RL-p18" buy-in

You don't have to worry any more. The testing is already done and both drivers are still live and kicking. And they did DELIVER. :)
Ilkka,
This is awesome news! :yay:
While we wait for these much awaited results, I had some thoughts that I am sure you would have contemplated too. How about some measurement results with real world movies? Pick the most intense most demanding tracks (there are several) so to be realistic we should narrow down to 3 movie tracks on which you can do some indepth outdoor measurements. Again this is simply a request. No expectations. What you already do for us Ilkka, is plenty. But I want to tickle your interest in this kind of test.
So here goes (only an example),.......
First, Calibrate your pre-amp receiver to 80dB reference at listening position with Avia in your own theater room. Next, let's say, we pick the "pod emergers/ground implodes scene in WOTW". Now you measure the input level to the amplifier to your sub/s at the most intense timestamps at reference level. This gives you a "reference point" for what one can expect in real world (any room similar to Ilkka's theater room). Now take the same setup outdoors and repeat the tests so that this time, you start from -6dB from "reference point", measure input level (should be -6dB from reference point as a double check) and measure Max output and other interesting parameters (the usual ones). Now you start increasing the input level to reference and as far beyond reference as you can safely go (maybe +6dB).
This will give us another dimension into a subwoofers performance that sweeps/mls tones cannot give.
The example test that I indicate here is pretty crude and not formalized, but it conveys the idea.
What do you think Ilkka? Is this something that you would be interested to do? Folks, what do you think?
Any suggestions? If there is enough interest.
My vote for the top 3 movies are,
1. WOTW (ground implodes/tripod emerges)
2. Flight of the Phoenix (plane crash)
3. Darla (tapping the fish tank).

-Jai
 
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